摘要
采用PCR方法从细颈囊尾蚴四川和云南两省的分离株中扩增出了线粒体细胞色素氧化酶Ⅱ亚基(COⅡ)的基因片段(pcox2),并结合GenBank中其他6种带属绦虫的同源序列进行了分析,探讨了细颈囊尾蚴与其他带属绦虫的亲缘关系。序列分析结果显示,分离自猪、山羊和绵羊的33株细颈囊尾蚴的pcox2长度均为523bp,序列间无插入、缺失,A、T、C、G碱基的平均含量分别为27.9%、41.4%、10.5%、20.1%,其中A+T含量(69.3%)明显高于G+C含量(30.6%),碱基组成存在明显偏倚。测定的33个细颈囊尾蚴分离株pcox2序列相似性较高(97.3%～100%);而与带科带属其他6种绦虫分离株的相似性均在90%以下。在构建的NJ树中,分布于我国四川和云南两省7个不同地理区域的细颈囊尾蚴聚为一支,且与地理区域、宿主没有直接的相关性。表明细颈囊尾蚴pcox2序列种内相对保守,种间差异较大,故可作为种间遗传变异研究的标记,从而为细颈囊尾蚴的种群遗传学研究和其相关疾病的诊断奠定基础。
Mitochondrial cytochrome c oxidase subunit Ⅱ（COⅡ） gene fragments（pcox2） of Cysticercus tenuicollis isolated from Sichuan and Yunnan provinces were amplified by PCR and sequenced.To clarify the phylogenetic relationship among C.tenuicollis and other Taenia species,these genes were compared with the homologous genes of other 6 Taenia species deposited in GenBank.The results showed that the lengths of pcox2 sequence of 33 isolates were all 523 bp,and there was no insert or deletion.The average contents of A,T,C and G were 27.9%,41.4%,10.5% and 20.1%,respectively.The contents of A＋T（69.3%） were obviously higher than that of G＋C（30.6%）.Homology analysis indicated that the homo-logy identity levels of nucleotides of pcox2 gene among the 33 isolates were high,ranged from 97.3% to 100%,but the homology identity levels of nucleotides of isolates in this study and other 6 kinds of cestodes in Taenia were below 90%.In the NJ tree,all the 33 isolates from the two provinces were grouped into a single cluster.There was no significant variation in pcox2 sequences within C.tenuicollis,while difference was obvious.pcox2 sequences may be used as genetic marker for population genetic studies of cestodes.The results of the present study can provide foundation for further studies of population genetics of C.tenuicollis,and for diagnosis of the resultant disease.
出处
《中国兽医科学》
CAS
CSCD
北大核心
2011年第7期684-690,共7页
Chinese Veterinary Science
基金
教育部"长江学者和创新团队发展计划"创新团队项目(IRT0848)
